SE 5.3.0 beta 3: Clicking in the experimental waveform sets the subtitle as dirty

Reminder: I'm running undocked. I load up a subtitle/video combination. Let it play a few seconds. Click in the waveform, which pauses playback. Look at the window title bar. There will be an asterisk indicating you've made changes to the subtitle, even though you haven't. I think I noticed this in beta 2 as well but I wasn't sure I hadn't accidentally brushed a key without noticing. But I'm completely certain now that this is happening.

On further experimenting, it is intermittent. Oh great. I do always try to make sure what I'm reporting is repeatable. We've had plenty of these one-time things that I'm wary of everything now. But I had a case where I started playback, clicked in the waveform, resumed playback, clicked in the waveform, maybe 7 or 8 cycles of this, & then oops, the asterisk appears in the window title bar. I thought it made a difference whether I was clicking within a subtitle or between subtitles, but I'm not sure that's a factor. All I know is that if I'm persistent, I can make it happen, but it's intermittent. So if you're trying to replicate this, don't take the evidence of your first attempt. Do it over & over until it happens. Just click in the waveform while playback is in progress, resume playback & click again. Eventually, that click will turn on the dirty flag.